Optimizing catheter based pulse application for intra-Arterial-Spin-Labeling in coronary arteries

Motivation: Intra-Arterial-Spin Labeling (iASL) could offer an alternative for myocardial perfusion measurements without the use of contrast agents by labeling blood with a catheter transmit RF-coil. Goal(s): To study the parameters influencing the iASL labeling efficiency inside the artery to improve the SNR. Approach: The complex iASL process is investigated with simulations and in-vitro measurements for different coil geometries (solenoid, loop), driving currents, coil orientations relative to the magnetic field, and blood flow velocities. Results: The simulations were in good agreement with measurements, show a maximal mean flip angle created by the labeling pulse of 105°, and a threshold behavior for the transmit current. Impact: The improvement of the labeling process inside coronary arteries started in this study, is an important step towards making ASL a viable method for myocardial perfusion quantification.